One of the most remarkable discoveries in non-equilibrium dynamics recently has been that quantum many-body systems can hydrodynamize far away from equilibrium [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}. Hydrodynamization refers to the stage of dynamical evolution in which the expectation values of the energy-momentum tensor and conserved currents start following the constitutive relations of hydrodynamics to a very good approximation. Remarkably, hydrodynamization can happen in both weakly coupled and strongly coupled systems even when they are far away from equilibrium and have large pressure anisotropies [9]}. Theoretically, hydrodynamization can be formalized in terms of a hydrodynamic attractor in phase space which is built out of a resummation of the divergent series of the late time effective hydrodynamic expansion such that the time-dependent energy-momentum tensor approaches that of the attractor for any arbitrary initial condition [3]}, [11]}, [12]}, [13]}, [14]}, [15]}, [7]}, [17]}, [18]}, [19]}, [20]}, [21]}, [22]}, [23]}, [24]}, [25]}, [26]}, [27]}, [28]}, [29]}, [30]}, [31]}, [32]}, [33]}, [34]}, [35]}, [36]}, [37]}, [38]}, [39]}, see [40]} for a recent review. The hydrodynamic attractor in diverse conformal systems, irrespective of whether they are weakly or strongly coupled (e.g., a kinetic system or a holographic strongly interacting field theory), are quasi-universal in the sense that the evolution is almost identical when the phase space is described by suitable variables (to be introduced in due course of time). The study of the hydrodynamic attractor has been extensively carried out in the context of the Bjorken flow to learn about the hydrodynamization of the quark-gluon plasma (QGP) produced in heavy-ion collisions
(see e.g. [41]}, [42]} for recent reviews),
although such a simplified set-up captures the longitudinal expansion only and not the transverse flow.
